Metadata Report for BODC Series Reference Number 1899987

• Metadata Summary

• Problem Reports

• Data Access Policy

• Narrative Documents

• Project Information

• Data Activity or Cruise Information

• Fixed Station Information

• BODC Quality Flags

• SeaDataNet Quality Flags

Metadata Summary

Problem Reports

No Problem Report Found in the Database

ACES-FOCAS James Clark Ross Cruise JR20070226 (JR165, JR170, JR174) Underway Meteorology Data Quality Document

Absolute Wind Speed and Direction

Several cycles in EWSBSS01 and EWDASS01 were assigned M (suspect) flags where anomalous changes in wind speed and direction were identified.

Air Temperature and Relative Humidity

Both CRELZZ01 and CRELZZ02 exhibit several periods with fairly constant data close to 100%. No flags were applied to these instances as data were not considered anomalous.

Data Access Policy

Open Data supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."

Narrative Documents

Gill Windobserver 70 (ultrasonic) anemometer

A solid state, heated ultrasonic anemometer. Designed for use within the aviation industry and for more extreme weather conditions. It measures the times taken for an ultrasonic pulse of sound to travel from the North transducer to the South transducer, and compares it with the time for a pulse to travel from S to N transducer. Likewise times are compared between West and East, and E and W transducer. The wind speed and direction (and the speed of sound) can then be calculated from the differences in the times of flight on each axis. This calculation is independent of factors such as temperature. It uses 150 Watts of electrical heating in the anemometer head to prevent icing. Wind speed accuracy is +/-2% at 12 m/s. Wind direction accuracy is +/-2 degrees at 12 m/s.

For more information, please see this document: https://www.bodc.ac.uk/data/documents/nodb/pdf/Gill_WindObserver70_2017.pdf

Kipp and Zonen PAR Lite Photosynthetically Active Radiation sensor

An atmospheric radiometer that measures photosynthetically active radiation (PAR) by means of a Teflon diffuser, an optical interference filter and a photo-diode detector. The sensor measures the PAR received over the entire hemisphere and the diffuser's sensitivity is proportional to the cosine of the angle of incidence of the incoming radiation. The optical filter has a spectral response of 400-700 nm (PAR wavelengths) and the photodiode creates a voltage output that is proportional to the incoming radiation.

Specifications

Further details can be found in the manufacturer's specification sheet.

Kipp and Zonen SP Lite and SP Lite2 Silicon Pyranometer

An atmospheric pyranometer that measures solar radiation over the range 400-1100 nm by means of a silicon photo-diode detector mounted in a diffuser. The sensor measures the radiation received over the entire hemisphere and the diffuser's sensitivity is proportional to the cosine of the angle of incidence of the incoming radiation. The photodiode creates a voltage output that is proportional to the incoming radiation. The SP Lite2 supersedes the SP Lite and features an improved sensitivity and faster response time than its predecessor.

Specifications

Further details can be found in the manufacturer's specification sheets for the SP Lite and SP Lite2.

Rotronic Hygromet MP102H and MP402H temperature and humidity probes

This meteorological probe measures humidity and temperature with the plug-in HygroClip HC2-S3 sensor module, and can also be equipped with a signal conditioned Pt100 temperature probe.

The two models differ in that the MP102H produces a voltage output while the MP402H produces a current output. Other characteristics are common to both models.

The specification sheet can be accessed here Rotronic MP102H and MP402H.

Specifications

Vaisala PTB210 Digital Barometer

The basic specifications for this pressure sensor are as follows:

• Manufacturer: Vaisala
• Type: Silicon capacitive sensor
• Model: PTB210
• Range: 900 - 1100 hPa
• Output: 0-5VDC
• Total Accuracy (20°C): ±0.30hPa
• Operating temperature: -40 to +60 deg C
• Weight: 110g
• Certification Ingress Protection: IP65

Further details can be found in the manufacturer's specification sheet.

Kongsberg Seatex Seapath 200 GPS and Gyrocompass

The Seapath 200 is a highly accurate, real-time heading, attitude and position information system that integrates the best signal characteristics of Inertial Measurement Units (IMU) and Global Positioning System (GPS), using a differential GPS method to acquire this data.

The high-rate motion data is obtained from the Seatex MRU5 inertial sensor and two fixed baseline GPS carrier-phase receivers. The raw data is integrated in a Kalman filter in the Seapath Processing Unit. The IMU contains an accurate linear accelerometer and Bosch Coriolis force angular rate gyros (CFG).

This system is equipped to utilise up to six different DGPS reference stations, it checks for consistency within measurements from the different sensors to ensure reliability and rejects noisy data or reports its inaccuracy. The data is available through various output protocols, RS-232, RS-422 and Ethernet.

This instrument is no longer in production; the main characteristics are presented below, and the specification sheet can be accessed here Kongsberg Seatex Seapath 200 .

Specifications

RRS James Clark Ross Cruise JR20070226 (JR165, JR170, JR174) Meteorology Instrumentation

Meteorological sensors were located on the ship's meteorological mast. The anemometer at a height of approximately 22.5 m, and the remainder at a height of 20 m above the water level. The following table presents the characteristics for the instruments collecting the data:

ACES-FOCAS Cruise RRS James Clark Ross JR20070226 (JR165, JR170, JR174) Underway Meteorology Processing Procedures Document

Originator's Data Processing

Two files with processed data were received at BODC. Wind data collection started on 06 April 2007 12:34 hours and the remaining parameters have data from 26 February 2007 12:48 hours to 17 April 2007 20:12 hours.

The procedures implemented throughout the cruise consisted of data retrieval from the previous 24h and logging those into subdirectories on the ship's intranet system. No further processing was done at that time.

All instruments, except the anemometer, which was on a mast 22.5 m above sea level, were located on the ship's meteorological mast, the sensors were placed side by side, 20 m above sea level.

Meteorological data originated from duplicate sensors located on the RRS James Clark Ross meteorological mast. The data was sent in two files and included data from: relative wind speed and direction, air temperature, pressure and relative humidity, PAR and TIR.

The processing procedures carried out by the originator after the cruise ended include:

• check for duplicate dates and times
• standardising time
• check for gaps in data
• check data against defined thresholds
• flagging
• unit conversion

File delivered to BODC

BODC Data Processing

The files mentioned above were selected for data banking as they contain the best version of processed meteorological parameters. Data were banked at BODC following standard data banking procedures, including reduction through averaging, checking meteorological channels for improbable values, working out absolute wind speed and direction, and screening the data for anomalous values. The originator's variables were mapped to appropriate BODC parameter codes as follows:

jr165_ocl_exactsec

jr165_anem_exactsec

All data expressed at measurement altitude. BODC's procedures included the transfer of originator's parameters into BODC codes and visual screening in Edserplo. N flags were applied during the transfer to absent values.

The meteorological data were collected with two sets of instruments. Data from both sensors, primary and secondary, were transferred and visually checked.

Absolute Wind Speed and Direction

Relative wind speed and direction were corrected for the ship's heading and speed using the gyrocompass heading, ship velocities (calculated at BODC from the main positional channels) and an anemometer orientation of 0° on the bow.

EWSBSS01 and EWDASS01 were assigned M flags in different instances:

• to all cycles flagged in ERWDSS01 and ERWSSS01
• to sudden changes in wind speed and direction identified during screening

Air Pressure

Both channels were screened and they exhibit a similar quality.

Air Temperature and Relative Humidity

All channels were screened and they exhibit a similar quality. Both CRELZZ01 and CRELZZ02 exhibit several periods with fairly constant data. No flags were applied to these instances as data were not considered anomalous.

Project Information

ACES- Antarctic Climate and the Earth System

Introduction

This project is part of the BAS GSAC five year research programme. It was funded by NERC and extended from 2005 to 2009.

ACES aims to investigate the atmospheric and oceanic links that connect the climate of the Antarctic to that of lower latitudes, and their controlling mechanisms. Specific research topics include the formation and properties of Antarctic clouds, the complexities of the atmospheric boundary layer and the importance to the global ocean circulation of cold, dense water masses generated in the Antarctic.

Data will be collected by a comprehensive programme of oceanographic measurements from BAS ships in the Weddell and Bellingshausen Seas and by the Twin Otter aircraft, which will allow for the study of cloud microphysics and air-sea-ice interaction. An ice core will be collected from the southwestern Antarctic Peninsula and will give a 150-year record of the strength of the circumpolar westerly winds. This data will be used to test and improve global climate models and a new regional atmosphere-ice-ocean model for the Antarctic.

ACES has two components: ACES-FOCAS (Forcings from the Ocean, Clouds, Atmosphere and Sea-ice) and ACES-ACCENT (Antarctic Climate Change and Nonlinear Teleconnections). It also links with several other projects: CACHE, GRADES, GEACEP, BIOFLAME, DISCOVERY2010 and SEC.

Scientific Objectives

The main objectives are:

• Understand the interactions between atmosphere, sea-ice and ocean at high southern latitudes
• Develop models to aid our understanding of Antarctic regional processes and enable the representation of essential regional phenomena in global models covering both the atmosphere and ocean
• Determine the nature and influence of the principal connections between Antarctica and the global climate system
• Determine the importance of water masses of Antarctic origin in the global ocean circulation
• Determine the sensitivity of the global climate system to processes occurring or originating in the Antarctic

Data Availability

Data sets collected during this project are available to the academic community.

Acronyms used in this text:

BAS- British Antarctic Survey

GSAC- Global Science in an Antarctic Context

CACHE- Climate and Chemistry: forcings , feedbacks and phasings in the Earth System

GRADES- Glacial retreat in Antarctica and Deglaciation of the Earth System

GEACEP- Greenhouse to ice-house: Evolution of the Antarctic Cryosphere and Paleoenvironment

BIOFLAME- Biodiversity, Function, Limits and Adaptation from Molecules to Ecosystems

DISCOVERY2010- Integrating Southern Ocean Ecosystems into the Earth System

SEC- Sun Earth Connections Programme

Data Activity or Cruise Information

Cruise

Complete Cruise Metadata Report is available here

Fixed Station Information

No Fixed Station Information held for the Series

BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle: